Serratus Anterior

- Discussion:
- serratus anterior arises from upper eight ribs, inserts on vertebral border of scapula, is innervated by long thoracic nerve, and
functions to draw scapula forward in sports such as a jab in boxing;
- paralysis produces characteristic prominence ("medial winging") of vertebral border of the
scapula; (consider Parsonage Turner)
- this is in contrast to paralysis of the trapezius which is associated w/ lateral winging;- origin:
- superior lateral surfaces of upper 8 or 9 ribes at the side of chest;
- arises from the upper 8 ribs, inserts on vertbral border of scapula;- insertion:
- costal surface of vertebral border along inferior angle of scapula;
- paralysis produces winging of the vertbral border of the scapula;- action:
- functions to draw scapula forward;
- abducts scapula and rotates it to point glenoid cavity superior;
- stabilizes vertebral border of scapla to thoracic cage, along with rhomboids and middle trapezius;- nerve supply:long thoracic, C5, C6, C7; - vascular supply: - it is supplied by circumflex scapular artery, which emerges at lateral border of scapula and divides into cutaneous scapular &
periscapular arteries;
- it has the advantage of a constant vascular pedicle and a well- hidden donor site, although the scar does spread;

- on exam, manually fix the inferior scapula to the chest wall in about of 35 deg of rotation, and note effect on forward flexion;
- slightly more or less rotation may improve forward flexion; - split pectoralis major transfer: - reconstruction for serratus anterior palsy is a two-incision, split pectoralis major transfer without fascial graft
- references:
- Pectoralis major transfer for serratus anterior paralysis
- Results of Transfer of the Pectoralis Major Tendon to Treat Paralysis of the Serratus Anterior Muscle
- Split pectoralis major transfer for serratus anterior palsy.
- spaculopexy: (from Vukov, et al. (1996))
- if physical exam demonstrates that manual fixation of the scapula will improve forward flexion, then a loose spaculopexy
(opposition of the scapula to the chest wall) may improve function;
- incision is made along the inferomedial border of the scapula;
- the infero-medial border of the scapula is defined;
- the scapula is oppose to the chest wall in the appropriate degree of rotation;
- the nearest distal rib is cleared of soft tissue;
- w/ appropriate retractors in place, a small drill hole is made in both the tip of the scapula and the adjacent rib;
- a Vicry ribbon (or similar material) is then passed circumferentially around rib and thru then thru the holes in rib and scapula;
- ref: Isolated Serratus Anterior Paralysis: A Simple Surgical Procedure to Reestablish Scapulo-humeral Dynamics. - Serratus Anterior Flaps:
- inferior three slips of serratus anterior may be used for free tissue transfer for coverage of dorsal & palmar defects in the hand;
- there are three separate slips that are easily divisible for contouring;
- this flap has low donor site morbidity;
- free scapular fascial flap resurfaced with skin graft provides less bulk than cutaneous scapular flap

advertisement

Orthopaedics and the US Military

Text Author

Dr. Wheeless enjoys and performs all types of orthopaedic surgery but is renowned for his expertise in total joint arthroplasty (Hip and Knee replacement) as well as complex joint infections. He founded Orthopaedic Specialists of North Carolina in 2001 and practices at Franklin Regional Medical Center and Duke Raleigh Hospital.